The present invention relates to methods for fabricating absorbent articles. Such methods usually include gluing and may include ultrasonic bonding, to combine elements and form absorbent articles.
Conventional methods of making absorbent articles, such as disposable diapers, are well known in the art. These methods usually rely on attaching leg cuffs, containment flaps, and other elements to the absorbent article as continuous webs of attachment material. Thus a continuous strip of material, such as leg cuff material, is continuously applied to the shell of an absorbent article. This method allows for high speed forming of absorbent articles.
Applicants"" process greatly reduces the complexity by placing leg cuffs and containment flap elastomeric elements on a continuous web or substrate. The continuous web is slit and folded to create two combined leg cuffs and containment flaps, and is then secured to an absorbent article web sausage.
By forming the leg cuffs and containment flaps separately from the web sausage, the number of processing steps or operations to the web sausage is reduced. This can increase the throughput speed of the manufacturing process.
Another of applicants methods forms the combined leg cuff and containment flaps on a substrate and then secures an outer cover to a first side of the substrate and a bodyside liner and absorbent core to a second side of the substrate, thus forming a further unique absorbent article.
The present invention relates to methods for fabricating absorbent articles, and focuses on forming leg cuffs and containment flaps. More particularly, the methods include applying elastomeric elements to a continuous web substrate and applying leg cuffs at longitudinally spaced locations along the substrate. The leg cuffs are transversely spaced from the elastomeric elements. One method further includes slitting the continuous web along its length at a center line to form two continuous web substrate portions, each having the leg cuffs and the elastomeric elements. The two continuous web portions are folded to form respective composite substrates of containment flap material, with leg cuffs spaced along the length of the containment flap material. The integral leg cuffs and containment flaps are then applied to a web sausage.
In one embodiment, opposed pairs of leg cuff pieces are longitudinally spaced along the length of each of the respective composite substrates. The opposed pairs of leg cuff pieces are disposed between the outer edges of the respective composite substrates and longitudinally extending elastomeric elements on the respective composite substrate.
In another embodiment the extensible leg cuffs are stretched, preferably to a dimension representing about 20% to 50% of the respective stretch-to-stop distance, when secured to the substrate.
In yet another embodiment, the leg cuff pieces comprise elastomeric strands secured to a generally nonelastomeric piece of material.
In still another embodiment, the leg cuff pieces, when secured to the substrate, substantially cover the leg cut-cuts.
Another embodiment includes the step of applying ultrasonic energy to the respective composite substrates to finish and smooth raw edges thereon.
In a further embodiment adhesive is applied along a center line of the respective composite substrate before mounting to the web sausage.
In a still further embodiment adhesive is applied along the longitudinal outside edge of the respective composite substrate adjacent respective leg cuff pieces before application to the web sausage.
In another embodiment of the invention, web structures for use as a combination leg cuff and containment flap are produced by supplying a substantially endless substrate portion having a length dimension, securing extensible leg cuff pieces to the substrate portion at longitudinally spaced locations, securing elastomeric elements longitudinally along the length dimension of the substrate portion in transversely spaced relationship to the leg cuff pieces, and folding opposing longitudinal outside edges of the substrate portion inwardly and securing the outside edges to facing portions of the substrate portion to form a composite containment flap substrate.
Another method of making an absorbent article includes securing elastomeric elements to a continuous first web substrate, slitting the substrate longitudinally to form a pair of first substrate portions, securing the first substrate portions to a second substrate, with the elastomeric elements between the second substrate and the pair of first substrate portions to form a base structure. An absorbent core and bodyside liner are applied to one side of the base structure and an outer cover is applied to the opposing side of the base structure to form a web sausage.
In one embodiment, the method includes the steps of folding outside edges of the base structure inwardly into a substantially J-shaped configuration and ultrasonically bonding the edges.
Another embodiment includes the steps of driving the base structure in a first nip at a first speed, then driving the base structure through a second nip at a second slower speed, such that ruffles are formed in the base structure between the first and second nips, the second nip securing the bodyside liner and absorbent core to the base structure while the base structure is in the ruffled condition.